Make sure it compiles on NS 4.0 for 3.3 headers
Create the conversion scripts
Convert your makefiles
For each of 6 conversion stages do:
Back up your code, I mean it!
Run stage N conversion script
Reread docs whilst converting
Recompile against stage N headers
Fix all the errors and warnings
Convert the .nibsCompile the app
Debug the app for correctness
Debug the app for retain/release errors